1. Field of the Invention
This invention relates to an anti-slip system for controlling the rotational speed of a drive wheel of a vehicle.
2. Prior Art
Recently, in the manufacture of a wheeled vehicle such as a motorcycle and a motor car, an engine portion and a frame or chassis have been improved to enhance a running performance of the vehicle on bad roads such as a muddy road and a snow-laden road. A tire traction, which is the ability to convert a rotational force of the drive wheel into a propelling force, can be enhanced to a certain extent by improving a pattern of the tire tread. Despite such improvements, when abruptly accelerating the vehicle, the drive wheel is still subjected to slip, so that the maximum tire traction can not be achieved. Thus, the drive wheel runs idle under such a condition so that a fuel consumption rate is worsened. It is known in the art that the maximum tire traction can be obtained when a slip rate of the drive wheel is at a predetermined level, for example, 5 to 10%.